title: Daxx functions as a scaffold of a protein assembly constituted by GLUT4, JNK1 and KIF5B.
abstract: We have previously reported the physical interaction between Daxx, the adaptor protein that mediates activation of the Jun amino-terminal kinase (JNK), and GLUT4, the insulin-dependent glucose transporter, interaction that involves their C-domains. Co-immunoprecipitation and two-hybrid-based protein-protein interaction studies show now that Daxx and GLUT4 interact with JNK1 through D-sites in their NH(2)-(aa 1-501) and large endofacial loop, respectively. Serum deprivation strongly enhances the association of JNK1 with Daxx and dissociates the kinase from GLUT4. SP600125, a potent JNK1 inhibitor, reduces the JNK1 activity associated with GLUT4 and the phosphorylation of two minor GLUT4 species in serum-starved 3T3-L1 adipocytes. In addition, Daxx interacts with kinesin KIF5B through the 6xTPR domain of the kinesin light chain, a domain engaged in the grab hold of protein cargo by kinesin motors that codistribute with JNK. Depletion of Daxx in 3T3-L1 adipocytes provokes the partial translocation of the GLUT4 retained in the GLUT4 storage compartment to endosomes.
authors.affiliation: Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Cantoblanco, Madrid, Spain. vlalioti@cbm.uam.es
authors.forename: Vasiliki S
authors.initials: VS
authors.lastname: Lalioti
authors.forename: Silvia
authors.initials: S
authors.lastname: Vergarajauregui
authors.forename: Yo
authors.initials: Y
authors.lastname: Tsuchiya
authors.forename: Sonia
authors.initials: S
authors.lastname: Hernandez-Tiedra
authors.forename: Ignacio V
authors.initials: IV
authors.lastname: Sandoval
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects / Q000201:enzymology; D000818:Animals; D000873:Anthracenes / Q000494:pharmacology; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D056970:Co-Repressor Proteins; D051275:Glucose Transporter Type 4 / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D055504:Insulin Receptor Substrate Proteins / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000378:metabolism*; D016547:Kinesins / Q000378:metabolism*; D051379:Mice; D008870:Microtubules / Q000187:drug effects / Q000378:metabolism; D048055:Mitogen-Activated Protein Kinase 8 / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D018832:Molecular Chaperones; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000187:drug effects; D051381:Rats; D044967:Serum
chemical_list: D000873:Anthracenes; D002352:Carrier Proteins; D056970:Co-Repressor Proteins; C491473:Daxx protein, mouse; D051275:Glucose Transporter Type 4; D055504:Insulin Receptor Substrate Proteins; D047908:Intracellular Signaling Peptides and Proteins; C526295:Irs1 protein, mouse; D018832:Molecular Chaperones; D009687:Nuclear Proteins; C432165:pyrazolanthrone; D048055:Mitogen-Activated Protein Kinase 8; C475469:Kif5b protein, mouse; D016547:Kinesins